<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        /*
        join
        -->讲数组转为一个字符串
        join(separator)
        */
        var arr=["hello","world","good"];
        var b=arr.join(" ");
        console.log(b);
    </script>
</body>
</html>